Punctuation. Colons

The content of these guidelines is taken from the third edition of the Vives University Network’s Interuniversity Style Guide for Writing Institutional Texts, an interuniversity project in which the UPC participates with the support of the Secretariat for Universities and Research of the Government of Catalonia.

General guidelines

A colon is receded by a complete sentence; what follows it may or may not be a complete sentence, and may be a list or even a single word.

University orientation provides a range of activities for new students: tours, workshops and social events. Research centres are facing a troubling situation: budgets are shrinking. They proposed the creation of a new post: unit coordinator.

Common mistakes: instead of a comma

Do not use a colon to substitute a comma.

*To complete your admission application: send the required documents by the end of the month. To complete your admission application, send the required documents by the end of the month.

Common mistakes with colons: with for example or such as

Do not use colons with for example or such as, which serve the same purpose as a colon.

*You must provide an outline of your research proposal, for example: objectives, methods, related research and expected outcomes.You must provide an outline of your research proposal, for example, objectives, methods, related research and expected outcomes.

Common mistakes with colons: after a preposition

Do not use colons between a preposition and its complement.

*The Council announced cutbacks in: research funding, international cooperation and staff development.The Council announced cutbacks in research funding, international cooperation and staff development.

Common mistakes with colons: two or more colons in a sentence

Never use more than one colon in a sentence.

*The Council's priorities are controversial: they have been praised and criticised by all groups: PDI, PAS and students.

Note, however, that you can use a semi-colon and a colon together in the same sentence.

The Government cutbacks have been devastating; protests are planned by many people working in the most affected areas: education, healthcare and social services.

Other uses of colons

When citing the name of a book which has both a title and a subtitle, separate the two with a colon. Do this even though no colon may appear on the cover or the title page of the book itself.

Human Towers: A Catalan Tradition

Use colons to write ratios.

Among students in the programme, women outnumbered men by more than 2:1.

However, in more formal contexts write out ratios in words.

Among students in the programme, women outnumbered men by more than two to one.